// Arup Guha
// 3/4/02
// This is an example of how templates are used
// to define a polymorphic stack

#include <iostream.h>

template<class T>
class stack {
	int count;
	T elems[100];
	public:
		stack() {count = -1;};
		char empty() {return count == -1;};
		void push(T e);
		T pop();
                T current();
		void print();
		stack<T> add(stack<T> s);
		stack<T> operator+(stack<T> s);
};

template<class T>
void stack<T>::push(T e) {
	
  if (count >= 99)
    exit(-1);
  else 
    elems[++count] = e;
  
}

template<class T>
T stack<T>::pop() {

  if ( empty() )
    exit(-2);
  else 
    return (elems[count--]);
		
}

template<class T>
T stack<T>::current() {
		
  return (elems[count]);
		
}


template<class T>
void stack<T>::print() {
	
  int i;
  for (i=0;i <= count;i++)
    cout << " " << elems[i] << " ";
  cout << "\n";
}

template<class T>
stack<T> stack<T>::add(stack<T> s) {
	
  if (count != s.count)
    exit(-3);
  else {
		
    stack<T> temp;
    int i;

    // Adds corresponding elements together and stores into the new stack.    
    for (i=0;i <= count;i++)
      temp.elems[i] = elems[i] + s.elems[i];
    temp.count = count;

    return temp;
  }
}

template<class T>
stack<T> stack<T>::operator+(stack<T> s) {
  return add(s);
}


main() {

        // Test a simple stack s.
        stack<int> s;
	int temp;
	temp = 1;
	s.push(temp);
	temp = 2;
	s.push(temp);
	temp = s.pop();
	cout << "Value is " << temp << "\n";
 
        // Create more stacks to test.
 	stack<int> s1;
	stack<float> f,f1;
	cout << s.empty() << endl;

        // Add to stack s.
	s.print();
	s.push(1);
	s.push(2);
	s.push(3);
	s.push(4);
	s.push(5);
	s.print();

        // Create s1 from s+s.
	s1=s.add(s);
	s1.print();

        // Get rid of elements in s.
	temp = s.pop();
	cout << "Temp is " << temp << "\n";
	s.print();
	s.pop();
	s.print();
	s.pop();
	s.print();
	s.pop();
	s.print();
        cout << " === " << s.pop() << " ===" << endl;
	s.print();

        // Add elements to stack f.
        cout << f.empty() << endl;
	f.print();
	f.push(1.4);
	f.push(2.4);
	f.push(3.4);
	f.push(4.4);
	f.push(5.4);
	f.print();

        // Create stack f1.
	f1=f + f;
	f1.print();

        // Pop off elements from f.
	f.pop();
	f.print();
	f.pop();
	f.print();
	f.pop();
	f.print();
	f.pop();
	f.print();
	cout << " === " << f.pop() << " ====" << endl;
	f.print(); 
}


/********  Output *******

Value is 2

 1 
 1  1  2  3  4  5 
 2  2  4  6  8  10 
Temp is 5
 1  1  2  3  4 
 1  1  2  3 
 1  1  2 
 1  1 
 === 1 ===
 1 

 1.4  2.4  3.4  4.4  5.4 
 2.8  4.8  6.8  8.8  10.8 
 1.4  2.4  3.4  4.4 
 1.4  2.4  3.4 
 1.4  2.4 
 1.4 
 === 1.4 ====

****************************/